Certain articles of manufacture such as charcoal cigarette filters, individual-sized packets of granular food products or condiments, capsuled pharmaceuticals, ammunition and the like require repetitive placement of precisely metered charges of particulate matter at some location along the production-line procession of the articles. Achieving sufficient speed in the mass production of such articles without sacrificing consistency, damaging the material and/or exacerbating spillage is challenging, particularly at elevated manufacturing speeds where ricochet and vibration may impair process control and consistency.
With machines of the prior art, process control usually suffers at high machine speeds from inconsistent metering and pulverization of the material, particularly in those prior machines where fast moving machine components are allowed to impinge stationary or relatively slow moving particulate material. For example, certain prior charcoal metering devices contain a supply of charcoal in a hopper and allow the rim of a rotating metering wheel to rotate through the relatively stationary collection of charcoal. Such an arrangement creates a pulverizing action upon the charcoal which generally increases with machine speed.
Excessive pulverization of the particulate material may alter the qualities of the final product unacceptably. Ricochet and escape of particulate matter during manufacturing operations with prior machines often create unacceptable deficiencies in the final product (such as smears or incomplete fillings) and precipitate undesirable machine "down-times" to effect clean-up of the machine and the surrounding work environment.
Accordingly an object of the present invention is to provide a method and apparatus capable of precisely metering discrete amounts of particular material at high machine speeds.
Another object of the present invention is to provide a method and apparatus which executes high speed delivery of metered amounts of particulate material without pulverization of the material even at high operational speeds.
Yet another object of the present invention is to provide an apparatus for delivering particulate material, which minimizes shearing action upon the particulate material.
Still another object of the present invention is to provide a method and apparatus which minimizes shear upon the particulate material by maintaining low relative velocities between the particulate material and portions of the machine coming into contact with the particulate material.
Another object of the present invention is to provide a method and apparatus which transfers particulate material with the assistance of vacuum so as to minimize scatter and promote consistency even at high machine speeds.
Yet another object of the present application is to provide a method and apparatus which applies vacuum to remove scattered material from sites intended to be free of material so as to enhance cleanliness of operation.
Still another object of the present invention is to provide a method and apparatus for high speed delivery of particulate material with minimal escape of the material.